Massalaah regarding marriage to a Shia woman and aqeeda

Assalamu alaikum. I am from Pakistan and belong to a Hanafi Muslim family.I follow the Ulama E Deoband,Alhamdulillah, whereas the rest of my family just classify themselves as Hanafi while not going into such a depth as to associate themselves with some Maslak.
The issue is that among my distant relatives, two men are married to Shia women. I would like to provide you information about the situation.
-One of the men is elderly,in his sixties and has been married for over forty years. – The other is young,in his late twenties and has been married for about 3-4 years. -Both marrriages have produced children.
Generally,Shias are considered as deviated but still within the fold of Islam,by most of my family.Hence there was no objection to these two marriages.
Now my questions are:

1) Should these two Shia women be considered Kafir by default,or should their Aqeeda be investigated?

2) If the reply to my first question is that these women will not be considered Kafirs ,but that there Aqeeda needs to be investigated, then what is the best method to do this investigation? Should their word be taken or what? (Just to let you know,my personal opinion is that both these women appear to be quite irreligious in the sense that they do not adhere to their Shia religion and hence I do not think that either of them has any of the Kufr beliefs of the Shias)

3) What is the status of these two men who have done nikah with Shia women?Have they become murtads?
Note: Mufti sahab the reason I wanted to ask this question was because I specifically want your opinion on this issue hence please do not tell me to refer to local ulama)

1. Investigate their Aqeedah. If they are Shia then there is no Nikaah.
2) Ask an Aalim who is an expert on Shias to question them otherwise they will resort to 'Takiyyah'.
3) If these ladies are Shia then these men are major sinners. They will become murtad if they knew they were marrying Shia Kafirs.